This application is a revision to R01 HD044923-01, a field-initiated study linked methodologically and theoretically with the Program Project Oracy/Literacy Development in Spanish-speaking Children (P01 HD39521). The objective of the proposed longitudinal project is to study language and literacy development among 600 children in grades I through 3 in Mexico. This study will use measures developed for and used in HD39521 currently underway in schools and communities in California and Texas. The proposed study will examine specific factors that have the potential to influence literacy development among Spanish speaking children in Mexico, with specific emphasis on elements that might differentiate the development of reading and related skills in English and Spanish. These factors include syllabic awareness as a mediator of phonemic awareness, formal reading instruction focusing on syllabic structures, family literacy practices including the traditional practice of storytelling, and access to literacy resources in the community. Students will be sampled from three public schools in different contexts in the Guadalajara metropolitan area: (1) a predominantly working class area with indigenous cultural influences, (2) a mixed working and middle class community with a large percentage of the population with family ties to the U.S., and (3) a predominantly middle class community. A cohort-sequential design involving 5 cohorts of children will be used to recruit a large longitudinal cohort of students spanning Grades 1 to 3. We will recruit cohorts of Grade 1, 2, and 3 students and classrooms, assess students at the beginning and end of the year, and observe in the classrooms 5 times each year--3 times with coded observation protocols used in our U.S. studies and twice with ethnographic protocols designed to identify features of Mexican classrooms that structured pre-coded protocols might not assess. In year 2, the Grade 1 and Grade 2 cohorts from year one are again followed, now in Grades 2 and 3, respectively, while a new cohort of Grade 1 students is recruited. This process is repeated in year 3. In total, the study includes 5 cohorts observed in the following grades-Cohort A: Gr 1-3; B: Gr 1-2; C: Gr 3; D: Gr 2-G3; E:Grl. Thus, three cohorts of 120 children are observed in Grade 1, three in Grade 2, and three in Grade 3. This design permits study of-factors influencing literacy development over time, while collecting comparative cross-sectional data on students in grades 1-3 at the participating schools. This project addresses the need for systematic study of literacy development in an alphabetic language other than English, that differs from English with respect to syllabic structure and orthographic transparency, and which develops in family and community settings with patterns of oral language and literacy use that differ from those experienced among English speakers in U.S. contexts.